I have an 02 Raptor with roughly 150-200 hrs..well i thought its about time to chnage the piston. I am going to be going with a ross or wiseco 11:1 piston, also putting a hotcamn stage 1 in. My question is, witht his many hrs am I going to bebale to go with a stock bore, or will my clearances not be proper now? Should I get it bored to a 686??Let Me know what ya think..Thanks in advance

 

If you want to stay at a stock bore, you should get your cylinder honed and cleaned up for the new piston. But if you want to bore up to a 686, the bore job alone won't cost very much.

 

I would go with the stage 2 with springs if your pulling the head anyway.Most here will agree.Pistons are available in many sizes. A 102mm is as big as the sleeve(cylinder) will go and will have to be replaced if it is ever worn past its limits. A 10 or 20 over piston should be fine and a good machine shop can bore and hone to the piston specs. With a stock bore I would still take it to a machine shop if your not familiar with measuring and honing and let them do it. The Wiesco piston is inexpensive and I have not seen or heard of one failing.The Ross (I own 2) is a very nice piston but is a little more. Cp is another option I have heard is good.
Also make sure the cylinder and the head are flat ( I use a large piece of glass and sand paper) and order the correct size head gasket if you go over bore.

 

I was considering the stage 2 cam, with new springs, the whole deal. But i have heard that im gonna lose a lot of bottom end on my bike. I do alot of different style riding and dont want to lose too much bottom end...how much will i actually lose going with a stage 2 over a stage 1..thanks

 

With the higher compression you are going to gain bottom end to compensate. The stage 2 pulls much harder and longer than the stage 1 but does have some bottom end loss. A gear change like going to a 12 on the front will make a HUGE difference. Which exhaust are you running?

 

Iam running a full Sparks X6 System, K&N Filter w adapter, no snorkle, holes in lid!

 

go with the stage 2. some people on the fourms started out with a stage one, and went to a two and coundent notice any low-end loss and said the stage 2 pulled MUCH harder.

 

And many people have the stage 1 setup and wouldnt trade it for anything else. The vast low and midrange is ideal for trail riding and for most xc and mx circuits. Granted the stg2 makes more hp but it leaves you with a bike that likes to rev, and not to put.

Its all about what you are going to be doing with the machine. Sparks pipes provide dramatic top end performance compared to other low end and mid range pipes but you sacrafice the low end pep. If you want more torque go with the stg 1. If you wind the engine out a lot and want more upper end power look towards a stage 2 or other aggressive cam.

 

just get a 11:1 and opt for the stage 2, and new spring, and while your at it, send you head to craycraft and have him port it, youll love it.

 

That's some good advice there but I think Bob's pump gas piston is 10.5:1, not 11:1.